Detonator for land mines

ABSTRACT

1,176,352. Land mines. INDUSTRIEWERKE KARLSRUHE, A.G. 9 Feb., 1967 [16 April, 1966], No. 6267/67. Addition to 1,005,388. Heading F3A. The land - mine of parent Specification 1,005,388 is modified by a cover member 3 having a spherical surface 51 with a centre of curvature which lies above the mine body, or in an upper part thereof, and which is supported by an annular member with an upper web 52a, having a conical surface supporting the surface 51 of the cover member, a cylindrical web 52c forming an axially directed guide, and a web 52b disposed between the webs 52a and 52c, and having a lower conical surface supported by a spherical surface 53 of an annular elastic buffer member 54, having a centre of curvature below the mine or in a lower part thereof. The web 52c is guided on a fuse receiver member 55 which is connected to the mine casing by rivets 56. The material of the spherical surfaces 51 and 53 is harder than that of the webs 52a and 52b, so that when the cover member is subjected to heavy loading its freedom of movement is ensured. The edge 52bk of the web 52b can abut an edge 52k of the member 55, and act as a shock absorber. A fuse is retained in the member 55 by springs 60. An arming device comprises lugs 67 which project above a cover 62 and entered from a rotatable ring 66 having recesses 68 into which pins 64 can move to release a slider 63 and allow it to be moved towards the fuse by a spring 69. An opening in the bottom of the casing 1 is closed by a metal cover 57. A heat fusible screw 58 is located in the side of the casing 1, together with an auxiliary detonator 59, so that the mine can be used for demolition work.

O. PECKSEN ET Al.

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Sept. 3, 196s Filed April l0, 1967 Sept. 3, 1968 o. PL-:cKsr-:N ET AL v DETONATOR FOR LAND MINES 2 Sheets-Sheet 2 Filed April lO, 1967 United States Patent O 3,399,620 DETONATOR FOR LAND MINES Otto Pecksen, Herrenalb, near Karlsruhe, Horst Ziolkowski, Karlsruhe, Baden, and Paul Madlener, Karlsruhe- Durlach, Germany, assignors to Industrie-Werke Karlsruhe Aktiengesellschaft, Karlsruhe, Germany, a corporation of Germany Filed Apr. 10, 1967, Ser. No. 629,770 Claims priority, application Germany, Apr. 16, 1966, .I 30,631 11 Claims. (Cl. 102-8) ABSTRACT OF THE DISCLOSURE A detonator for use in a land mine with an all around tiltable release member which is formed in part by a pressure cover resistant to bending stresses and which is supported on lthe mine casing by an elastic outer ring body and an additional hard elastic inner ring body.

An annular supporting member is provided in vertical section with three arms of which one arm forms a centrally disposed guide portion engaging a centrally arranged detonator receiving member. This annular supporting member is provided with two conical surfaces, one on each of the other two arms and inclined to one another. The inner ring body of the mine engages one of the two conical surfaces which is softer, and a buffer ring carried by said detonator receiving member has a hard spherical surface engaging the other softer conical surface on the supporting member.

The invention relates to a detonator for use in land mines to be dropped from airplanes, moving tanks or the like, with a release member which is tiltable all around and which, when subjected to perpendicularly impacting detonation waves, particularly of the nuclear type, makes an idle movement while when subjected to obliquely impacting forces it tips from its bearing surface and releases the tiring pin. The detonator is further constructed as a pressure cover resistant to bending stresses which by its elastic outer ring body and an additional intermediate hard-elastic inner ring body engages the mine casing. The inner ring body has a convex surface with a radius which is smaller than the highly curved counter surface of the pressure cover. To avoid a lateral shifting of the mine cover when hitting the ground, the cover edge is bent upwardly and is stiffened by a suitably secured reinforcement.

In a prior art device of this type, as for instance is disclosed in the copending patent application Ser. No. 556,637, filed on June l0, 1966, by Paul Madlener et al., the pressure cover is not iixedly attached to the mine casing. When the mines are dropped from a greater height, the cover rim under certain circumstances may strike the ground first so that it intercepts the entire striking force and is thereby pushed to the side. The result is that the cover no longer returns to its starting position because the detonator release means are no longer in alignment and the outer elastic ring body is distorted and may even tear away.

There are other disadvantages in prior art devices. The spherical plastic buffer may under heavy stress impress itself into the conical counter surface of the pressure cover so that no longer sphere moves on sphere, but a cone is formed within a cone and the pressure cover is severely impeded in or entirely prevented Ifrom its movements. Consequently,kthe tilting distance and the releasing forces of `the pressure cover required for a release increase incalculably. Since the ideal center of rotation during a tilting movement'of the pressure coverV lies on ice the underside of the mine, `the direction of pressure of the traction chains of a tank moving over the mine may extend through the ideal center of the pressure cover so that due to the absence of a lever arm there is no longer any torque and the mine will not -be caused to detonate.

If by a ca-reless handling the detonator is not completely screwed into place, it may happen that after the expiration of the safety period usually provided, the detonator moves into the release position and actually causes a detonation.

If the mine hits the ground in an unfavorable manner, the bottom closure made of plastics may be destroyed and the blasting cap may be damaged and detonate.

In order to overcome the aforedescribed disadvantages, the invention provides a supporting mem-ber which has a three-armed cross-section and a straight, axially extending guide portion With two conical surfaces oppositely inclined to each other. On top of the upper counter surface of said two conical surfaces rolls off a downwardly curved spherical surface which is part of the pressure cover and has its center of rotation above the mine body or in the upper section of the same, respectively, and the inclined lower counter surface is engaged by a buifer ring having an upwardly curved spherical surface with its center of rotation in the lower section of or below the mine body, respectively.

The supporting member is of conical shape; the material of the counter surface on the pressure cover is harder than that of the supporting member so that under severe load placed upon the pressure cover the sphere is pressed into the cone thereby assuring the movability of the pressure cover, namely the moving of sphere on sphere.

The supporting member is further longitudinally movably arranged on a central detonator receiving member and rests with one cone against the spherical surface of a plastic buffer. If the plastic buffer is deformed a predetermined amount by a central load, then the annular edge of the supporting member comes to rest upon an annular receiving surface of the central detonator receiving member which acts much like a shock absorber. The spherical buffer is necessary to dampen or to absorb the impact of the mine hitting the ground or of detonation shocks, respectively. It has been proven that a dampening of a sutiicient degree is possible only when the buffer is spherical.

In accordance with the present invention, the detonator is no longer threaded into place, but is only axially inserted and is fixed in its position by two axially extending locking springs which with their rounded ends engage a corresponding collar on the detonator. The springs are of such a construction that when the detonator has erroneously been inserted only loosely, it will automatically be locked between the two springs when the twist cap is twisted on, whereby the energy required therefor is less than the energy required for activating the detonator.

A sliding member on the 4threaded cover is held by two oppositely arranged pins on a slanting milled surface. The pins are supported by a rotary ring. This ring is rotated by means of laterally projecting cams and has two recesses into which when the ring is rotated the pins are moved by the action of a spring, thus releasing the slidable member. The shape of the recesses and the slope of the milled surface assure a slow and nearly jerk-free descent of the sliding member.

In accordance with the present invention the bottom closure is made of metal, and a lateral detonator screw cap made of a low melting synthetic material serves as a melting fuse.

When the pressure cover is tilted, the spherical counter surface slides in such a manner in the conical supporting 3 member that the edge of the pressure cover moves parallel to the dish-shaped wall of the explosive container.

These and other objects of the invention will be described in further detail with reference to the accompanying drawings in which:

FIG. 1 is a sectional view of the mine according to the invention;

FIG. 2 illustrates the rotary ring provided with cams, and

FIG. 3 illustrates an exterior view of the mine.

Referring to FIG. l, the pressure cover 3 for the mine casing 1 which has a hard-elastic spherical surface 51 and whose center of rotation Mo is disposed above the mine, rests -on top of the upper conical surface 52a of an annular supporting member 52 having in vertical section three arms 52a, 52b and 52C. The arm 5211 which forms an angle with the conical surface 52a', engages with its conical surface 52b the upper inclined spherical surface 53 of a buffer ring 54. The buier ring -54 is concentrically mounted in an annular recess of a centrally located receiving member 55 for the detonator and engages the vertical arm 52e` of the supporting member 52 which in turn is guided on the upper annular portion of the centrally located receiving member 55 of the detonator. The upper spherical surface 53 of the buffer ring 54 has its center of rotation Mu on the center line of the mine in its lower section. The buffer ring 54 is also made of a hard-elastic plastic. The supporting member 52 is made of a flexible material so that the spherical surface 51 of the cover 3 and the spherical surface 53 of the buffer ring 54 engaging the conical surfaces 52a and 52b, respectively, of the supporting member 52 will retain their spherical shape.

If under a central load which is in excess of a predetermined pressure the buffer ring 54 is deformed by an amounts m (see FIG. 1), then the annular edge 52b K of the inclined supporting arm 52b comes to rest upon an annular receiving surface 55K of the centrally located detonator receiving member 55 (shock absorber). Owing to the spherical shape of the buffer, any blows during the impact of the mine or detonation vibrations, respectively, are dampened or absorbed.

The central detonator receiving member 55 is connected to the top portion of the mine casing 1 by rivets 56.

The bottom closure 57 is made of metal.

As a melting fuse serves a lateral detonator threaded connection 58 made of a low melting plastic material. A blasting cap 59 is inserted only when the mine is used for blasting bridges, railway installations and the like, but is omitted when the mine is to be dropped from airplanes, tanks and the like.

In the event that in the prior art devices the detonator is not completely threaded into place, it would be possible that it is moved into the release position and caused to detonate after the predetermined time period in the detonator has run off. In order to prevent this, the present invention provides for a simple axial insertion of the detonator rather than the prior threaded-in-type. In accordance with the present invention, two axially extending springs 60 are provided for holding the detonator in its position in that the upper rounded ends of the two springs engage a suitable collar or rib on the detonator. The springs 60 are so constructed that under a pulling stress they develop an inwardly directed momentum. If the detonator by carelessness has been inserted only loosely, it will be automatically engaged by the springs 60 when a threaded cap 61 in the pressure cover is screwed into place since the energy required therefor is less than the energy required to release the detonator.

Below a protective cover -62 is arranged a sliding member 63 which does not penetrate the cover. This sliding member 63 is held in engagement with an inclined milled surface 65 by two pins 64 arranged opposite each other. The pins 64 are engaged by a rotary ring 66 arranged below the cover 62 and the ring 66 is operated by cams 67 projecting from the cover 62. The rotary ring 66 has two recesses 68 into which upon a clockwise rotation of the ring 66 the pins 64 are moved by the action of a helical spring 69 arranged between the cover 62 and the sliding member 63, thereby releasing the slidable member 63. The shape of the recesses 68 and the inclined milled surface 65 assure a slow and almost completely smooth descent of the sliding member 63..

What we claim is:

1. In a detonator for use in land mines to be dropped from '-airplanes, lmoving tanks, and the like, having an all-around tiltable release member which when subjected to perpendicularly impacting detonation waves, particularly of the nuclear type, makes an idle movement, while when said release member is subjected to obliquely impacting forces it is caused to tip from its bearing surface and release la firing pin, said release member forming a part of a pressure cover resistant to bending stresses and which is supported by the mine casing by an elastic outer ring body and an additional intermediate hardelastic inner ring body, said inner ring body having a convex surface with a radius smaller than the curved counter surface 0f said pressure cover, the edge of the mine cover being bent upwardly and stiffened by a reinforcement to prevent a lateral shifting of said mine cover when hitting the ground, the improvement comprising an annular supporting member which in vertical section is provided with three arms 52a, 52b 52C of which one arm 52C forms a straight, axially extending guide portion, said supporting member having two conical surfaces 52a', 52h inclined to each other, of which the upper conical surface 52a is engaged by a downwardly curved spherical surface 51 forming part of the pressure cover 3 and having its center of rotation Mo above the rnine body, while the lower conical surface 52h' which is inclined toward said upper conical surface 52a' engages a buffer ring having an upwardly curved spherical surface 53 whose center of rotation Mu is disposed in the lower portion of the mine body.

2. A detonator for use in land mines according to claim 1, in which said straight guide portion 52o of the supporting member 52 is coaxially mounted on a centrally located detonator receiving member 55 which is tixedly connected to the top portion of the mine casing.

3. A detonator for use in land mines according to claim 1, in which said spherical surfaces 51, 53 are provided on a member which is a made of a material harder than the material of which `the supporting member is made on which said conical surfaces 52a', 52b' are arranged.

4. A detonator for use in land mines according to claim 1, in which above a predetermined pressure exerted on said supporting member 52 an annular edge of the same engages an annular receiving surface 55K provided on the centrally located detonator receiving member 5S thus acting as a shock absorber.

5. A detonator for use in land mines according to 'claim 1, in which the centers of rotation Mo, Mu of said spherical surfaces 51, 53 are disposed on the center axis of the mine.

6. A detonator for use in land mines according to claim 1, in which said detonator is axially inserted into its position and is held in operative position by springs one end of which is rounded for exerting an inwardly directed momentum upon the detonator.

7. A detonator for use in land mines according to claim 1, including within said cover two .pins 64 arranged opposite to one another, one end of said pins engaging an inclined surface 65 and the other end engaging a rotary ring 66 which is operated by cams protruding outwardly from said cover 62.

8. A detonator for use in land mines according to claim 7, in which said rotary wing 66 has two recesses 68 into which upon a clockwise rotation of said ring '66 said pins 64 are moved by the action of a helical spring 5 6 69 arranged between said cover 62 and an axially slidable detonator threaded connection 58 made of a low melting member 63 thereby releasing Said slidable member 63. synthetic material.

9. A detonator for use in land mines according to claim 8, in which said recesses are curved gradually to References Cited assure a smooth entering of said sliding member. 5 UNITED STATES PATENTS 10. A detonator for use in land mines according t0 2,857,842 10/1958 Malm 102-8 claim 1, including a bot-tom closure 57 made of metal. 3,205,817 9/ 1965 Maplener et al, 102-8 11. A detonator for use in land mines according to claim 1, including a melting fuse in the form of a lateral SAMUEL W. ENGLE, Primary Examiner. 

